A new total variation diminishing scheme for the calculation of one-dimensional flow in inlet and exhaust pipes of internal combustion engines

Total variation diminishing (TVD) schemes have been recently introduced for the calculation of the one-dimensional unsteady flow in the inlet and outlet pipes of internal combustion engines. This paper describes the flux difference splitting technique (with first- or second-order upwind fluxes) for the classic TVD schemes. To avoid problems at nodes with a section change, a new TVD scheme is developed. This paper further describes a method to impose the boundary condition at the pipe end, independent of the numerical scheme used. This is shown for a reservoir inlet of the pipe and a subsonic outlet flow. For two test cases (the shock-tube and the tapered-pipe calculation), the new TVD algorithm is compared with the classic TVD schemes. The evaluation shows that the new cell—vertex TVD scheme with superbee limiter in two stage form combines a high accuracy with an exact representation of the mass flow in each of the nodes.